Bypassing duplex filter

Abstract

The disclosed invention relates to a transceiver system having a bypass signal path that enables low power consumption. The transceiver system has transmission path and a reception path. The transmission path provides a signal from a transmission chain to an antenna for wireless transmission. The reception path provides a signal from the antenna to a reception chain. A duplex filter that provides isolation between the transmission and reception paths is connected between the antenna and the transmission and reception paths. A bypass signal path selectively exchanges signals between the transmission chain and the antenna along a conductive path that bypasses the duplex filter. By using the bypass signal path to selectively exchange signals between the transmission chain and the antenna the insertion loss of the duplex filter can be mitigated, allowing for the transceiver system to operate at a lower power.

What is claimed is: 
     
       1. A transceiver system, comprising:
 a first signal path comprising a plurality of transmission paths respectively configured to convey signals at different frequencies between an antenna port and a signal processing unit; 
 a second signal path comprising a plurality of reception paths respectively configured to convey signals at different frequencies between the antenna port and the signal processing unit; 
 a plurality of duplex filters, wherein each duplex filter is connected between a respective one of the transmission paths and a respective one of the reception paths, wherein each one of the plurality of duplex filters is configured to provide isolation between the respective one of the transmission paths and the respective one of the reception paths; 
 a bypass signal path configured to be selectively connected between the antenna port and the signal processing unit along a conductive path that by-passes the duplex filters; 
 a first switching element having an input connected to a power amplifier and a plurality of outputs corresponding to a first end of the plurality of transmission paths and the bypass signal path, respectively; 
 a second switching element having a plurality of inputs corresponding to a second, opposite end of the plurality of transmission paths and the bypass signal path, respectively, and an output connected to the antenna port; and 
 a switching controller configured to generate one or more control signals that operate the first switching element and the second switching element; 
 wherein the one or more control signals comprise periodic waveforms repeating at identical intervals; and 
 wherein the first switching element and the second switching element are configured to switch the power amplifier and the antenna port between each one of the plurality of transmission paths and the bypass signal path, respectively. 
 
     
     
       2. The transceiver system of  claim 1 ,
 wherein the first signal path comprises a transmission chain configured to provide a signal to be transmitted to the antenna for wireless transmission; and 
 wherein the second signal path comprises a reception chain configured to receive a received signal from the antenna. 
 
     
     
       3. The transceiver system of  claim 1 , wherein the first and second switching elements are configured to selectively connect the signal processing unit to the antenna port by way of either the bypass signal path or one of the plurality of the transmission paths. 
     
     
       4. The transceiver system of  claim 2 , wherein the switching controller is configured to generate the one or more control signals that operate the first and the second switching elements to connect the transmission chain to the antenna port by way of one of the plurality of the transmission paths when the reception chain is operated to convey the received signal and by way of the bypass signal path when the reception chain is operated to not convey the received signal. 
     
     
       5. The transceiver system of  claim 4 , wherein the switching controller comprises:
 a memory element configured to store data corresponding to a transmit and receive timing; and 
 a processor configured to access the data and to generate the one or more control signals based thereupon. 
 
     
     
       6. The transceiver system of  claim 2 ,
 wherein the transmission chain comprises the power amplifier; and 
 wherein the bypass signal path extends from a first position downstream of the power amplifier and upstream of the duplex filters to a second position downstream of the duplex filters. 
 
     
     
       7. The transceiver system of  claim 1 , wherein the bypass signal path comprises a low pass filter. 
     
     
       8. The transceiver system of  claim 1 , wherein the transceiver system comprises a LTE-FDD (Long Term Evolution frequency division duplexing) system. 
     
     
       9. A transceiver, comprising:
 a transmission chain configured to provide a signal to be transmitted to an antenna port for wireless transmission; 
 a reception chain configured to receive a received signal from the antenna port; 
 a plurality of transmission paths respectively configured to convey signals at different frequencies between the transmission chain and the antenna port; 
 a plurality of reception paths respectively configured to convey a received signals at different frequencies between the antenna port and the reception chain; 
 a plurality of duplex filters, wherein each duplex filter is connected between a respective one of the transmission paths and a respective one of the reception paths and configured to provide isolation between the respective one of the transmission paths and the respective one of the reception paths; 
 a control unit configured to operate the transmission chain and the reception chain at a same time and at separate times; 
 a bypass signal path configured to be selectively connected between the transmission chain and the antenna port along a conductive path that bypasses the duplex filters; 
 a first switching element having an input connected to a power amplifier in the transmission chain and a plurality of outputs corresponding to a first end of the plurality of transmission paths and the bypass signal path, respectively; 
 a second switching element having a plurality of inputs corresponding to a second, opposite end of the plurality of transmission paths and the bypass signal path, respectively, and an output connected to the antenna port; and 
 a switching controller configured to generate one or more control signals that operate the first switching element and the second switching element; 
 wherein the one or more control signals comprise periodic waveforms repeating at identical intervals; and 
 wherein the first switching element and the second switching element are configured to switch the power amplifier and the antenna port between each one of the plurality of transmission paths and the bypass signal path, respectively. 
 
     
     
       10. The transceiver of  claim 9 , wherein the switching controller is configured to generate the one or more control signals that operate the first and second switching elements to connect the transmission chain to the antenna port by way of one of the plurality of transmission paths when the reception chain is operated to convey the received signal and by way of the bypass signal path when the reception chain is operated not to convey the received signal. 
     
     
       11. The transceiver of  claim 9 ,
 wherein the transmission chain comprises the power amplifier; and 
 wherein the bypass signal path extends from a first position downstream of the power amplifier and upstream of the duplex filters to a second position downstream of the duplex filters. 
 
     
     
       12. The transceiver of  claim 9 , wherein the bypass signal path comprises a low pass filter. 
     
     
       13. A method of reducing insertion loss in a transceiver system, comprising:
 providing a transceiver having a reception chain connected to an antenna port by way of a plurality of reception paths and a transmission chain selectively connected to the antenna port by either one of a plurality of transmission paths that connect the antenna port by way of a respective duplex filter or a bypass signal path that connects to the antenna port by way of a conductive path that bypasses the duplex filters; and 
 operating a first switching element and a second switching element to connect the antenna port to the transmission chain by way of the bypass signal path when the reception chain is operated not to convey a received signal based on one or more control signals from a switching controller, wherein the one or more control signals comprise periodic waveforms repeating at identical intervals; 
 wherein the first switching element has an input connected to a power amplifier in the transmission chain and a plurality of outputs corresponding to a first end of the plurality of transmission paths and the bypass signal path, respectively, and the second switching element has a plurality of inputs corresponding to a second, opposite end of the plurality of transmission paths and the bypass signal path, respectively, and an output connected to the antenna port; and 
 wherein the first switching element and the second switching element are configured to switch the power amplifier and the antenna port between each one of the plurality of transmission paths and the bypass signal path, respectively. 
 
     
     
       14. The method of  claim 13 , wherein operating the first switching element and the second switching element to connect the antenna port to the transmission chain by way of the bypass signal path when the reception chain is operated not to convey the received signal further comprises:
 operating the first and the second switching elements to couple the transmission chain to the antenna port by way of one of the plurality of transmission paths; 
 operating the reception chain to receive a signal from the antenna port during a first time-slot; 
 operating the reception chain to not convey the signal from the antenna port during a subsequent time-slot; 
 operating the first and the second switching elements to couple the transmission chain to the antenna port by way of the bypass signal path, after operating the reception chain to not convey the signal from the antenna port; and 
 transmitting a signal from the transmission chain along the bypass signal path to the antenna port during the subsequent time-slot. 
 
     
     
       15. The method of  claim 13 , wherein the transceiver comprises a LTE-FDD (Long Term Evolution frequency division duplexing) system.